Elevator control system



June 12, 1934. R. E. DE CAMP ELEVATOR CONTROL SYSTEM Filed Jan. 28, 1931 Inventor lit/amt Patented June 12, 1934 UNITED sme- 1,962,389 ELEVATOR CONTROL SYSTEM Ray Delqa bt Glendale,'.Calif., assignor to Consolidated. Steel. Corporation, Los Angeles,

Calif., a corporation of California Application 28,

1931, Serial No. 511,771

aciai s. (c1. rs1 29) My invention relates to a motor-control tem and has particular reference to 'a when system for an elevator.-

Elevator control systems embodyingthe fea ture of having the elevator car started by an attendant who rides upon the car and permitting the elevator to be automatically stoppedin response to calls for service registered Bypassengers operating push buttons atthe floors past which the car moves or-huttons within the car. Previous systems however, have depended upon the provision of self-tidldirigcircuits for the power controlling apparatus to maintain the same in active condition until the car'arrives' at the floor corresponding to a buttonwhich' has been pressed, or such"'seltf-holdingcircuits are employed in connection with an'automatic 1aming device which maintains 'the 'mot'or' mechanism active during the deceleratiohf a'nd ac curate landing of the car at the riser;

Such systems have the disadvantagehowever, that the elevator car is not under the'cofi trol of the attendant at all times since' lti's iln possible for him to stop the car at aiiyplace other than a floor level unless he operates some additional emergency device for causing="si1chstops. Y

It is therefore an object of {my'inve'ntieri to provide a system of elevator control:-in which the car switch provided upon the oa'rQto be manipulated by the attendant'at' alltimes dominates the control of the elevator.--'

Another object of my invention to provide an elevator control systemin 'whieh tlie attendant on the car must hold the car switch' in running condition in order'that thecafi 'shall be operated and shall be decelerated-andstopped at an accurate level with the floors.

Another object of my invention-is te -provide a control system as described-in the' preceding paragraph in which 'but'tons -withim'the car or buttons at the floor landings may be operated to automatically decelerate aud -stop the car in response thereto, while the 'ca'r'switch is held in running position.

Another object of my invention is to provide a control system as described in the preceding paragraph in which no self-holding circuits are provided for any of the motor'conti'ol switches and relays. U 7

My invention will be described-with reference to the accompanying drawing wherein the sole' figure is a diagrammatic view illustrating an elevator control system constructed in accordance with my invention.

Referring to the drawing, I have illustrated an elevator car C operated upon hoisting cables Ca which pass over a hoisting drum D to a suitable counterweight Cw. The hoisting drum D1 is illustrated as being directly coupled tothe armature of an elevator motor EM which is illustrated as of the separately excited type having itsfield winding EMF connected to a source of electric supply illustrated by line conductors L1 and L2. V v

The conductor system for the elevator motor EM is illustrated as of the variable voltage type in'which'the-armature EM of themotor EM is connected in loop circuit with the armature G of a generator G. A series field winding GSF is connected in theloop circuit and is so proportioned to the windings of the armature and field of the generator G that the current produced by the generator will cause the elevator motor to operate at substantially the same speed indepe'ndent of variation in'load upon the car.

The generator armature G is illustrated as being continuously driven by means of a driving m'otor'DM illustrated as of shunt wound type having its armature DM' and its field winding DMF' connected in parallel relation to the source of "electric supply Ll and L2. The generator G is provided with a separately excitedfield winding GF Wh1Ch '1S connected to an' up-direction switcli 1' or a down-direction switch 2 so that operation of one or the other of these switches causes current to flow through the field winding GF-eitherin one direction or the other to cause the car C to either ascend or descend. The speed'o f the car C is controlled by means of increasing-bi decreasing the amount of current sul plied to'the field winding GF, the circuit for the field winding GF extending through a pair of resistors R1 and 3.2 which are arranged to short-circuit 'it by means of speed control switches 'UI and UH respectively when the car is to travel upwardly, and switches DI and DH respectively when the car is'to travel downwardly.

The operation of the direction switches 1 and 2 and the speed switches UI, UH, DI and DH are illustrated as being directly controlled by means of a car switch Cs located upon the car to be manipulated by an attendant thereon.

-In order to insure that when the car C is to be stopped at a floor it will be accurately leveled with the floor, I have illustrated a landing system operable by car position controlled switches, the particular switches illustrated being of the inductor relay type in which a relay for each step'of slow-dow'nand stop is provided for each direction of travel of the car. A stopping relay USR and intermediate speed relay UIR and a high speedrelay UHR are illustrated for the up-direction of travel to respectively control the tip-direction switch 1, the up-intermediate speed switch UI and the up-high speed switch UH, while a similar set of relays DSR, DIR and DHR respectively control the down-direction switch to the down-intermediate speed switch DI and the down-high speed switch DH. It will be understood by those skilled in the art that suitable inductor plates of magnetic material are located adjacent each of the floors past which the car moves for successively operating the inductor relays. It will also be understood that the relays are normally inefiective to be actuated by their inductor plates until the coils of these relays are energized as the car approaches successive points in advance of the floor to automatically slow down and stop the car accurately at the landings.

I have illustrated a call registering system for permitting prospective passengers to automatically stop the car at the floors upon which they are waiting so that they may board the car to travel to their destination. This call registering system is illustrated at the left hand side of the drawing as comprising an up-push button and a down push-button for each floor.

Only the buttons 2U and 2D tor the second floor are illustrated, though it will be understood by those skilled in the art that similar buttons are provided for each of the floors. A push button relay is associated with each of the buttons; that associated with button 2D is designated by the reference character 2BR.

In order to withdraw the calling system to normal after the elevator car has responded thereto, each of the button relays has associated therewith, a cancellation relay, these being designated by the reference characters 2UC and 2DC respectively.

In order to permit the operation of the elevator controlling apparatus by the push buttons when the car approaches the corresponding floor, I have illustrated as a. part of the call registering system, a floor selector FS which comprises a plurality of groups of segmental contacts arranged to be traversed by a movable arm MA in correspondence with the movement of the car past the respective floors. The floor selector FS is illustrated as comprising a suitable base B (indicated by dotted lines) upon which a row of up-floor call segments UF are mounted, one segment for each floor served by the car. A similar set of segments for the down-direction. designated by the reference character DE. A row of up-cancellation segments UK are. illustrated as including a segment for each floor served by the car, connected to the corresponding cancellation relay 2UC etc. A similar set of down-cancellation segments DX are provided for cancelling down calls.

Also, I have illustrated 2 sets of car call segments UCC and DCC connected to the car push button, one of which is illustrated at 4C as mounted upon the car for registering the desire of passengers to leave the car at the various floors. The button 40 is illustrated as being associated with the fourth floor, while there will be a corresponding button for each of the other floors served by the car but which for the sake of simplicity are not illustrated in the drawing.

A pair of call responsive relays, one for each direction of travel are provided to be operated in response to registered calls for service to cause the car to stop in response to such calls. The call responsive relay for the up-direction is designated by the reference character UCR while that for the down-direction is designated DCR.

The operation of my system will best be understood with reference to an assumed elevator operation. Assuming that the car is at the lower terminal or first floor and it is desired to have the car ascend, the attendant on the car may operate the car switch C. in a clock-wise direction to complete a circuit for the up-direction switch 1, which circuit extends from line conductor Li thfiough conductor 10, contact 11, segment 12 and contact 13 on car switch Cs, conductor 14 the coil of up-direction switch 1, conductor 15. normally closed contact 16 on ub-stdpi lhziinductor relay USR and conductors 17 18 to' llne conductor In.

Up directlhn switch 1, when energized, closes its contact member a and b to complete a circuit for sending current in one direction through the generator separately excited field winding GF, which circuit extends from line conductor L1 through conductors 19 and 20, contact members b coup-direction switch 1, conductors 21 and 22, field windin'g GF, conductors 23 and 24, contact member a on rip-direction switch 1, conductor 26. WyR-i and R: and conductor 26 to line conductorfi-iil- The generator field winding GF is thus supplied with current, the quantity of which is limited by the resistors R1 and R: and the generator armature G' will supply a small voltage to the elevator motor EM to cause the car C to travel upwardly in slow speed.

To cause, the car to accelerate to a higher speed, the attendant may move the car switch C. to a iurth er clockwise position to complete a circuit for the up-intermediate speed switch UI which circuit extends from line conductor Ll through coniiuetor 10, contact 11, segment 12 and contact127 on car switch Cs, conductor 28, the coil of lip-intermediate speed switch UI, conduetor 29, normally closed contact members 30 on up iiitermediate speed inductor relay UIR and conductors 17 and 18 to line conductor L2.

- lip-intermediate speed switch UI when energized closes. its contact member a to short-circult resistor R1 to thus exclude this resistor from the circuit ot the field winding GP, to thus increase the amount of current supplied to the field winding and to thus increase the speed of the car C.

To further increase the speed of the car, the attendant may move the car C; to a still further clockwise position to complete a circuit for the lip-high speed switch UH which circuit extends from line conductor Ll through conductor 10, contact 'member 11, segment 12 and contact member 31 on car switch Cs, conductor 32, the coiljof -up-hlgh speed switch UH, conductor 33, normally closed contact member 34 on up-liigh s" d inductor relay UHR and conduetors. 1'! and 18 to line conductor L2.

n-hiah speed switch UH, when energized, closes its Contact members a to short-circuit the remaining resistor R: to exclude the same from the circuit of field winding GF so that this winding is now supplied with full line voltage and the car C operates at high speed.

The will continue to operate at high peed as long as the attendant holds the car switch in the position to contact contact members 11, 13; 2'7 and 31. It will be observed that the circuits for the up-direction switch 1,-

the tip-intermediate speed switch UI and the up'hlgh speed switch UH extend in series relation through their associated car switch contacts and their associated inductor relay contacts so that the opening of either of these sets of contac s will cause deenergization of the emaciated switch.

. Thus at any time that the attendant returns the car switch C5 to 011 or central position, the switches UI and UH will be deenergized and the car will be immediately stopped. However, if the car switch is held in running positon, the car will not stop unless the inductor relays UHR, UIR and USR are operated to open their contacts.

The operation of the inductor relays can only occur when their coils are energized and these relays respectively pass inductor plates mounted at predetermined distances in advance of each of the floors.

I have illustrated the coils of the inductor relays UHR, UIR and USR as being controlled by the up-coil responsive relay UCR so that the coils of the inductor relays are not energized except when the coil responsive relay UCR is energized.

Assuming that a person at the second fioor desires to travel upwardly and operates the button 2U to signify his intention, such operation will complete a circuit for the second floor up button relay 2UR, which circuit extends from line conductor L1 through conductor 40, push button 2U, conductor 41, the coil of relay 2UR, conductor 42, normally closed. contacts of the second floor up-cancellation relay 2UC and conductor 18 to line conductor L2.

Relay 2UR, when energized, completes a selfholding circuit for itself which extends from line conductor L1 through conductor 43, normally open contacts a on relay 2UR, conductor 44, to the coil of relay 2UR and thence to line conductor L2 as previously described. Thus, relay 2UR operates its contact members b to supply current from line conductor L1 to the second floor up call segment 45, which circuit extends from line conductor L1, through conductor 46, contact members b and relay 2UR, conductor 4'7, to junction point 48, hence one branch extends by way of conductor 49 and conductor 50 to segment 45 on floor selector FS. It will be observed that while I have illustrated only one car, my system is adapted to a bank or a plurality of cars by merely connecting corresponding fioor selector on all of the cars to conductor 49 so that upon operation of the button 2U the second floor up segments on the floor selectors for all of the cars will be supplied with current.

As the car C approaches the second floor, the movement arm MA on floor selector FS moves in correspondence with the movement of the car and causes contact brush 51 to engage contact segment 45. In the case of a high speed elevator car, this engagement will probably occur before the car starts from the first floor or will occur almost immediately upon the starting of the car.

The engagement of contact brush 51 with segment 45 causes completion of a circuit for up call responsive relay UCR, which circuit extends from line conductor L1 to segment 45 as previously described, and thence extends from contact brush 51 through conductor 52, the coil of relay UCR and conductors 53 and 54 to line conductor L2.

The energization of relay UCR closes its contact members b to complete a circuit for energizing the coils of inductor relays UHR, UIR and USR. At the same time, relay UCR closes its contact members a to complete a self-holding circuit for itself, which circuit extends through contact member 55 on car switch Cs. This circuit may be traced from line conductor L1 through conductor 10, contact member 11, contact segment 12, and contact member 55 on car switch Cs (which will be engaged as soon as the car switch Cs has been moved in a clockwise direction), conductor 56, resistor 57, contact member a on relay UCR, conductor 58, and coil of relay UCR, and thence conductor line 2 as previously described.

Contact members b on relay UCR, when closed complete a circuit for energizing the coils of conductor relays UHR, UIR and USR, which circuit extends from line conductor L1 through conductor 10, and thence to the coils of inductor relays USR, UIR and UHR in parallel relation, the opposite ends of these coils being connected in parallel relation to conductor 59 which extends through contact members b on relay UCR and conductors 60 and 54 to line conductor L2.

If the car approaches a certain distance away from the second floor the relay UHR will be brought adjacent its inductor plate for the second floor and will be operated to open its contact members 34 to thus break the circuit for high speed relay UH to reinsert resistor R1 in the generator field winding circuit, to thus slow down the car to intermediate speed.

As the car approaches still closer to the second floor inductor relay UIR will pass its inductor plate and be operated to open its contact members 30 to break the circuit for intermediate speed relay UI to reinsert resistor R1 in the field winding circuit to slow the car down to its slowest or landing speed. Again, as the car approaches still closer to the floor, that is, arrives approximately at the floor level, the inductor relay USR will pass its inductor plate and will be operated to open its contact member 16 to deenergize the up-direction switch 1 and thus bring the car to rest at the second floor level.

It will be observed that during all this time the circuit for the call responsive relay UCR has been maintained because the attendant was holding the car switch in running position, it being assumed that the inductor relays are of the type which when once actuated hold their contacts in the actuated position until their coils are deenergized. Thus the car will be brought to an accurate stop at the second floor even though the attendant holds the car switch in running position.

In order to re-start the car it is necessary that the operator or attendant shall return the car switch to off position and again operate this switch to running position. Upon returning the car switch to the oil position the holding circuit through contact 55 on the car switch Cs for the relay UCR is broken so that the relay is deenergized permitting the contacts of the inductor relays to reclose. The re-starting of the car is the same as described for the initial start.

When the car arrives at the second floor level the movable arm MA on the floor selector FS will be in such position that its brush 61 will engage contact segment 62 of the group of upcancellation segments UK. This segment 62 is the second fioor cancellation segment and when engaged by the brush 61 a circuit is completed to the up-cancellation relay for the second floor 2UC. This circuit extends from line conductor L1 through conductors 63 and 64, brush 61 on movable arm MA, segment 62 and conductor 65, to a junction point 66 whence a conductor 6'7 extends to a second junction point 68 at which it connects with a conductor 69 leading to the coil of the cancellation relay 2UC, the opposite end of the coil being connected to conductor 18 and thus to the opposite line conductor L2.

It will be observed that the conductor 67 extends to the corresponding second floor cancellation segments on all of the floor selectors for all of the cars in the bank, so that whichever car answers the call for second floor up travel will restore that call to prevent other cars from stopping in answer thereto.

The energization of cancellation relay 2UC causes it to open its contacts to break the holding circuit for push button relay 2UR, thus restoring this relay to normal deenergized condition ready to be again operated when persons at the second floor desire to travel upwardly.

Assuming that the passenger who boarded the car at the second floor desires to travel to some other floor and so informs the attendant, the attendant may operate the proper push button on the car (corresponding to button 40 illustrated upon the car) to thereby supply current to the corresponding car call segment on the floor selector FS. For example, if the button 4C is operated to cause the car to stop at the fourth floor the current will be supplied to segment 70 constituting one of the group of up car call segments UCC, this circuit extending from line conductor L1 through conductors 10 and '71, button 4C, conductor '72, to segment '70.

Thus, as the car approaches the fourth floor, the contact brush 73 on the movable arm MA will engage segment '70 to complete therethrough a circuit for again operating up call responsive relay UCR, this circuit extending from the brush 73 through conductor 74 to conductor 52 and thence to relay UCR as previously described.

The slowing down and the stopping of the car at the fourth floor is then accomplished as described for the second floor stop.

Operation of the car in the down direction is similar in all respects to that described for the up direction except that in this case, down direction switch 2, down intermediate speed relay DI, down high speed relay DH and down call responsive relay DR will be operated instead of up direction switch 1 and the speed switches bearing the prefix U. Also, the down inductor relays will be actuated to stop the car in response to the down button 2D and its associated relays.

It will therefore be observed that I have provided an elevator system in which the car is at all times under the control of a car switch on the car to be operated by an attendant thereon. The car may be stopped automatically, leveled with the floor in response to the operation of a call button at the floor or a call button within the car corresponding to that floor, while at any time the attendant may stop the car independent of the buttons by merely returning the car switch to off position.

While I have shown and described the preferred embodiment of my invention, I do not desire to be limited to any of the details shown herein except as defined in the appended claims.

I claim:

1. In an elevator control system, a car operable past a floor, a motor for operating said car, a manually operable car switch on said car, a normally ineffective car position controlled switch operable in response to the approach of a car to said fioor, a controlling switch for said motor, a circuit for operating said controlling switch which is closed by movement of said car switch from a first position to a second position, and which is opened by return of said car switch to said first position, said circuit being independently opened by said car position controlled switch when said switch is actuated, and means for maintaining said car position controlled switch in actuated condition when actuated, until said car switch is returned to said first position.

2. In an elevator control system, a car operable past a floor, a motor for operating said car, a manually operable car switch on said car, a normally ineffective position-controlled switch operable in response to the approach of a car to said floor, a controlling switch for said motor, a circuit for operating said controlling switch which is closed by movement of said car switch from a first position to a second position, and which is opened by return of said car switch to said first position, said circuit being independently opened by said car position controlled switch when said switch is actuated, and means for preventing reclosing of said circuit until said car switch has been returned to said first position.

3. In an elevator control system, a car operable past a floor, a motor for operating said car, a direction switch for controlling the direction of movement of said motor, one or more speed switches for controlling one or more speeds of operation of said motor, a car position controlled switch for each of said direction and speed switches, and a circuit for each of said direction and speed switches including in series relation corresponding contacts of said car switch and the contacts of the associated car position controlled switch.

4. In an elevator control system, an elevator car operable past a floor, a motor for operating said elevator car, control switch means for controlling the operation of said motor, a car switch on said car for manipulation by an attendant thereon, a circuit for operating said control switch means to be opened or closed by manipulation of said car switch to opened or closed position, respectively, a car position switch in said circuit operably responsive to the approach of the car to said floor for opening said circuit independent of said car switch, said car position switch being normally ineffective for operation as said car approaches said floor, and means operable by a passenger waiting on said 11001 for rendering said car position switch effective for operation.

5. In an elevator control system, an elevator car operable past a floor, an inductor relay having a coil, a magnetic plate and contacts operable by said coil only when the coil is energized and is adjacent the plate, a motor for operating said car, a control switch for said motor and a circuit for operating said control switch including in series relation a car switch on said car manually operable by an attendant on the car and normally closed contacts on the inductor relay to be operated by said relay when the car approaches said floor, a passenger operated call registering system, and means operated bythe registration of calls from said floor for energizing said inductor relay coil.

RAY E. DE CAMP. 

